U-type two-cycle radial engine



May 23, 1939. R. M.-HAZEN U-TYPE TWO-CYCLE RADIAL ENGINE 2 Sheets-Sheet 1 Filed Dec 30, 1936 Worm/d Wane/z May 23, 1939. R. M. HAZEN U-TYPE TWO-CYCLE RADIAL ENGINE Filed Dec. 30. 1956 2 Sheets-Sheet 2 Patented May 23, 1939 UNITED STATES PATENT OFFICE U-TYPE TWO-CYCLE RADIAL ENGINE Application December 30, 1936, Serial No. 118,212

Claims.

This invention relates to radial engines and particularly to radial two-cycle internal combustion engines having so-called U type cylinders.

Such U type cylinders are well known, and

5 consist generally of two associated cylinder barrels having a common combustion chamber, there being inlet ports in one cylinder and exhaust ports in the other, with pistons in each cylinder barrel, themselves controlling the inlet and exhaust ports respectively. The pistons in each U type cylinder move together in the same direction on the power and compression strokes but the exhaust piston usually has a slight lead on the inlet piston in order that the exhaust ports may be opened before the inlet ports.

In radial engines with U type cylinders, the cylinder barrels of each U type cylinder have been arranged parallel to the crankshaft, the crankpins for the respective inlet and exhaust cylinder barrels being offset a suiflcient amount to give the desired lead to the exhaust piston; alternatively this has been achieved by oflsetting the cylinder barrels instead of'the crankpins.

The object of the invention is a radial U type 25 two-cycle engine with a cylinder arrangement such that as many as ,6, 8 or even.10 U type cylinders (according to the power desired) may be disposed around the crankshaft, without any change in the overall dimensions of the engine. 30 A further object of the invention is a short, light engine with a crankshaft cheap to produce and balance.

The above and other objects of the invention will be apparent as the description proceeds.

In a radial engine, according to the invention, the crankpins are in line and each U type cylinder has its cylinder block barrels arranged in such a way that the exhaust cylinder barrel is disposed somewhat in advance of its associated inlet cylinder barrel, with respect to the direction of rotation of the crankshaft. for which the engine is designed. Furthermore, all the U type cylinder blocks are offset from each other alternately in two banks in planes transverse to the crankshaft, separated from each other by approximately half the distance between the cylinder barrel centers of each U type cylinder.

The drawings show an eight cylinder U type radial engine according to the invention.

In the drawings:

Fig. 1 is a view of the engine in elevation.

Fig, 2 is a somewhat enlarged plan view of a part of Fig. 1.

Fig. 3 shows diagrammatically, the relative positions of therespective inlet and exhaust pistons in one of the U type cylinders at the point where the exhaust port is about to be opened on the power stroke.

Fig. 4 shows diagrammatically the relative positions of the respective inlet and exhaust pistons in one of the U type cylinders at the point where the exhaust port is about to be closed on the compression stroke.

Fig. 5 is an enlarged part sectional view on line 5-5 of Fig. 2.

Fig. 6 is a part sectional view on line 6--8 of Fig. 5.

The cylinders i to l are equally spaced circumferentially of the engine. Each of the cylinders includes an inlet cylinder barrel such as 9 and an exhaust cylinder barrel such as It having a common combustion chamber I and provided respectively with inlet and exhaust ports II and i2 and pistons l3 and II.

As shown in Fig. 2, the cylinder barrels are arranged desaxe (i. e., in such a way that their center lines are parallel to, but displaced on opposite sides of a plane containing the adds I! of the crankshaft) with the exhaust cylinder barrel ll of each U-type cylinder block disposed somewhat in advance of its associated inlet cylinder barrel], with respect to the direction oi rotation of the crankshaft for which the engine is designed. The odd numbered cylinders I, 3, 5 and I are offset axially of the crankshaft from the even numbered cylinders 2, 4, B and 8 in two banks spaced apart by a distance equal to approximately one-half the distance between the cylinder bore centers of cylinder barrels 8 and Ill.

The pistons l3 and il in the cylinders I, 3, I and 1 have connecting rods l5 and i6 respectively, while the pistons I3 and It in cylinders 2, 4, 6 and I! have connecting rods l5 and it.

As shown in Figs. 5 and 6, all the connecting rods IE, it and i5, it have segmental slipper ends 2|, 22 and 2|, 22' respectively. They are identical and are connected through the slipper ends to the single crankpin I! o! the engine crankshaft ill, in four different planes, axially thereof. 45

Slipper retaining ring bearings 23, 2|, 25, 2B, 21 and 2B encircle the slipper ends 2|, 22 and M, 22'; as shown in Fig. 5, the retaining ring bearings 24 and 21 serve to support the adjacent slippers 2|, 2| and 22, 22 respectively, thus pro viding more. bearing area with greater compactness and less weight in the moving parts.

Figs. 3 and 4 show the result achieved by the desaxe arrangement of the cylinder barrels of each U cylinder block, (with the exhaust cylin- 55 der barrel i disposed somewhatin advance of its associated inlet cylinder barrel 9 with respect to the direction of rotation of the crankshaft) in conjunction with an exhaust port l2, higher in the cylinder wall of the exhaust cylinder lli than the inlet port H in the inlet cylinder 9. It will be seen that the arrangement provides for opening of the exhaust port 12 before the inlet port 9, on the power stroke, with closing of the exhaust port at the same time orlater than the inlet port, on the compression stroke. The closing of the inlet and exhaust ports at approximately the same time enables the engine to work satisfactorily with a lower blower pressure than would be satisfactory with the exhaust port closing before the inlet port.

As compared with an engine having offset crankpins for the same port timing, the oflsetting of the cylinder barrels in a direction transverse to the crankshaft provides an engine in which the exhaust piston has a maximum lead at the time when this is required, (1. e., at about the time of opening of the inlet port) while both inlet and exhaust pistons approach the end of their strokes more nearly at the same time, particularly at the end of their compression stroke, at which time they are both moving at their slowest, and approximately in unison, towards and away from their dead center; this can be shown to give more eflicient combustion by virtue of the greater quenching eflect obtained.

In addition, the crankshaft with its single crankpin is cheaper and more easily balanced than a crankshaft with oflset crankpins, while in conjunction with the use of slipper type connecting rods, engines can be built for a wide horsepower range by varying the number of identical cylinders, and using identical crankshafts, connecting rods and bearings, without any change in the overall dimensions of the engine.

I claim:

1. In a radial two cycle engine having a plurality of U type cylinders, each including a pair of cylinder barrels with a common combustion chamber, pistons in the cylinders, a crankshaft, and connecting rods for the pistons, there being piston controlled inlet ports in one cylinder barrel and exhaust ports in the other of each pair, the arrangement of the exhaust cylinder barrel of each U type cylinder somewhat in advance of its associated inlet cylinder barrel with respect to the direction of rotation of the crankshaft, with alternate U type cylinders offset from each other axially of the crankshaft in two banks spaced apart a distance equal to approximately one-half the distance between the cylinder bore centers of the cylinder barrels of each U type cylinder, said connecting rods of all the pistons having a common crankpin axis on the crankshaft, and being in one or another of four dif ferent planes transverse to the axis thereof.

2. The combination according to claim 1 in which the connecting rods of all the pistons have slipper ends in bearing engagement with a single crankpin on the crankshaft, the slipper ends being in one or another of four difierent planes transverse to the axis of the crankshaft.

3. The combination according to claim 1 in which the connecting rods of all the pistons have slipper ends in bearing engagement with a single crankpln on the crankshaft, and retaining ring bearings encircling the slipper ends, at least one of the retaining ring bearings serving to support the slipper ends in two adjacent planes of the said four different planes.

4. The combination according to claim 1 in which the exhaust ports in the walls of the exhaust cylinder barrels are higher than the inlet ports in the walls of the inlet cylinder barrels whereby in each U type cylinder, on the power stroke of the pistons, the exhaust port will be opened before the inlet port, and on the compression stroke of the pistons the exhaust port will be closed not earlier than the inlet port.

5. In a radial two cycle engine having a plurality of U-type cylinders, cachincluding a pair of cylinder barrels with a common combustion chamber, pistons in the cylinders, a crankshaft, and connecting rods for the pistons, there being piston controlled inlet ports in one cylinder barrel and exhaust ports in the other of each pair, the arrangement of the exhaust cylinder barrel of each U-type cylinder somewhat in advance of its associated inlet cylinder barrel with respect to the direction of rotation of the crankshaft, alternate U-type cylinders being offset from each other axially of the crankshaft in two banks spaced apart a distance equal to approximately one-half the distance between the cylinder bore centers of the cylinder barrels of each U-type cylinder, said connecting rods of all the pistons having slipper ends in bearing engagement with a single ci'ankpin on the crankshaft, and being in one or another of four different planes transverse to the axis thereof, and retaining ring bearings encircling the slipper ends, at least one of the retaining ring bearings serving to support the slipper ends in two adjacent planes of the said four difl'erent planes.

RONALD M. HAZEN.

CERTIFICATE OF CORRECTION.

Patent No. 2,159,209.

ROllALD 11. HAZEN.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 1, first column, line 57, for the words "cylinder has its cylinder block barrels" read cylinder block has its cylinder barrels; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 8th day of August, A. n. 19 9.

(Seal) Leslie Frazer, Acting Commissioner of Patents.

der barrel i disposed somewhatin advance of its associated inlet cylinder barrel 9 with respect to the direction of rotation of the crankshaft) in conjunction with an exhaust port l2, higher in the cylinder wall of the exhaust cylinder lli than the inlet port H in the inlet cylinder 9. It will be seen that the arrangement provides for opening of the exhaust port 12 before the inlet port 9, on the power stroke, with closing of the exhaust port at the same time orlater than the inlet port, on the compression stroke. The closing of the inlet and exhaust ports at approximately the same time enables the engine to work satisfactorily with a lower blower pressure than would be satisfactory with the exhaust port closing before the inlet port.

As compared with an engine having offset crankpins for the same port timing, the oflsetting of the cylinder barrels in a direction transverse to the crankshaft provides an engine in which the exhaust piston has a maximum lead at the time when this is required, (1. e., at about the time of opening of the inlet port) while both inlet and exhaust pistons approach the end of their strokes more nearly at the same time, particularly at the end of their compression stroke, at which time they are both moving at their slowest, and approximately in unison, towards and away from their dead center; this can be shown to give more eflicient combustion by virtue of the greater quenching eflect obtained.

In addition, the crankshaft with its single crankpin is cheaper and more easily balanced than a crankshaft with oflset crankpins, while in conjunction with the use of slipper type connecting rods, engines can be built for a wide horsepower range by varying the number of identical cylinders, and using identical crankshafts, connecting rods and bearings, without any change in the overall dimensions of the engine.

I claim:

1. In a radial two cycle engine having a plurality of U type cylinders, each including a pair of cylinder barrels with a common combustion chamber, pistons in the cylinders, a crankshaft, and connecting rods for the pistons, there being piston controlled inlet ports in one cylinder barrel and exhaust ports in the other of each pair, the arrangement of the exhaust cylinder barrel of each U type cylinder somewhat in advance of its associated inlet cylinder barrel with respect to the direction of rotation of the crankshaft, with alternate U type cylinders offset from each other axially of the crankshaft in two banks spaced apart a distance equal to approximately one-half the distance between the cylinder bore centers of the cylinder barrels of each U type cylinder, said connecting rods of all the pistons having a common crankpin axis on the crankshaft, and being in one or another of four dif ferent planes transverse to the axis thereof.

2. The combination according to claim 1 in which the connecting rods of all the pistons have slipper ends in bearing engagement with a single crankpin on the crankshaft, the slipper ends being in one or another of four difierent planes transverse to the axis of the crankshaft.

3. The combination according to claim 1 in which the connecting rods of all the pistons have slipper ends in bearing engagement with a single crankpln on the crankshaft, and retaining ring bearings encircling the slipper ends, at least one of the retaining ring bearings serving to support the slipper ends in two adjacent planes of the said four different planes.

4. The combination according to claim 1 in which the exhaust ports in the walls of the exhaust cylinder barrels are higher than the inlet ports in the walls of the inlet cylinder barrels whereby in each U type cylinder, on the power stroke of the pistons, the exhaust port will be opened before the inlet port, and on the compression stroke of the pistons the exhaust port will be closed not earlier than the inlet port.

5. In a radial two cycle engine having a plurality of U-type cylinders, cachincluding a pair of cylinder barrels with a common combustion chamber, pistons in the cylinders, a crankshaft, and connecting rods for the pistons, there being piston controlled inlet ports in one cylinder barrel and exhaust ports in the other of each pair, the arrangement of the exhaust cylinder barrel of each U-type cylinder somewhat in advance of its associated inlet cylinder barrel with respect to the direction of rotation of the crankshaft, alternate U-type cylinders being offset from each other axially of the crankshaft in two banks spaced apart a distance equal to approximately one-half the distance between the cylinder bore centers of the cylinder barrels of each U-type cylinder, said connecting rods of all the pistons having slipper ends in bearing engagement with a single ci'ankpin on the crankshaft, and being in one or another of four different planes transverse to the axis thereof, and retaining ring bearings encircling the slipper ends, at least one of the retaining ring bearings serving to support the slipper ends in two adjacent planes of the said four difl'erent planes.

RONALD M. HAZEN.

CERTIFICATE OF CORRECTION.

Patent No. 2,159,209.

ROllALD 11. HAZEN.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 1, first column, line 57, for the words "cylinder has its cylinder block barrels" read cylinder block has its cylinder barrels; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 8th day of August, A. n. 19 9.

(Seal) Leslie Frazer, Acting Commissioner of Patents. 

